Pan Size

I have a question about a heart shaped pan I have. I'm trying to determine what size it is, but have lost the insert to it. It's a Wilton 502-1298. Does anyone have an idea of how to find out? Thank you in advance.

If you're just wanting to know how many cups of batter it takes, fill it with water and then measure the water.

Thank you cali4dawn. I was trying to figure out what size it was so I could figure out how many servings I would get out of it. I'm going to be making for a friend's birthday party and want to make sure I take enough cake. Thank you.

Thank you very much for the serving size suggestion. I don't know why I didnt think about just measuring out the servings. Common sense left me for a bit there. Thanks for helping me regain a bit back. LOL